Catalytic process for treating hydrocarbon oils



m R. P. RUSSELL 2,26%94 I GTLYTIC PROCESS FOR TBEATING HYDROCARBON GILSFiled Feb. s, 1959 @ACTO R.

5A TEE Savary* f H JPRCGFIV INLET f3 if BSORBER on. Quv'LE-r 5E PARA TDFCQCL En HEATER .SEPBEH TAR y rnc-rs1. Ac To/VA TIA/ 6 Ta wsa Zww .s1-1:.4 MIN c CHAMBER Patented Dec. 3 0, 1941 cATALr'ric PROCESS Foa TREATmGmnocAnBoN oms Robert P. Russell, Miuburn, N. J., assignor to StandardOil Development Company, a corporation of Delaware l ApplicationFebruary 9, 1939, serial No. 255,390

' s claims. l(c1. 1961-52) This invention relates to the treatment ofhydrocarbon oils by catalytic processes such as catalytic cracking,catalytic reforming, catalytic dehydrogenation' and the like.

The invention will be described with particular reference to catalyticcracking butA it should be understood that it is not Hunted thereto. The

drawing is a semi-diagrammatic view in sectional elevation of one typeof apparatus which may be used.

In vthe catalytic cracking of heavy hydrocarbon oils to produce lowerboiling hydrocarbons of high octane number suitable for motor fuel, theheavy oil is firs-t vaporized, and the vapors are then passed through areaction chamber wherein they come in contact with a catalytic materialsuch as an adsorptive clay, activated alumina or activatedhydrosilicates of aluminum. There arevseveral different methods by whichcontact oi' the vapors with the catalyst may be brought about. Onemethod is to pass the vapors through a reaction chamber provided withstationary catalyst. Another method is to pass the vaporsover acontinuously moving 'mass of granular catalyst. Another method is tosuspend the nely divided catalytic material in the oil before it isintroduced into the reaction chamthereon of contaminants such as tarryor coky material. Consequently, means must be provided for removingthese contaminants from time to time in order to` regenerate thevactivity of the catalyst. `When a stationary catalyst is used, it can beseen that the catalytic cracking process must be intermittent, that is,there is first a cracking cycle and. then a regenerating cycle. When amoving granular catalyst or a powdered catalyst is used, the process maybe continuous because the cracking can continue in one vessel while thespent catalyst is being regenerated in another vessel'.

Because of the necessity for periodic regeneration'of the catalyst, itwill be appreciated thatit is desirable to make the active life of theca talyst as long as possible and to make the regenerating period asshort as possible:

The present invention is directed primarily tov improved methods ofcarrying out the catalytic process in the vpresence of powderedcatalyst,

whereby the active life of the catalyst may be substantially lengthened.The nature of these improvements will be fully understood from thefollowing description read with reference to the accompanying drawing.

According to the present invention, the catalytic process is carried outin the presence of hydrogen or gases rich in lfree hydrogen, in thepresence of powdered or finely divided catalyst, and the hydrogen isused as the medium in which the finely divided catalyst is suspendedprior'to its introduction into the reaction zone. The process isoperated at temperatures, pressures, space velocities and-withquantities of hydrogen such that there is no net consumption of freehydrogen and in fact there may be a net production of hydrogen.

Referring to the drawing, numeral I designates a pipe through which oilis introduced into the system. The oil passes through a heating means 2wherein it is vaporized and thence flows through line 3 into the top ofa reaction chamber 4. In the event some of the heavier fractions ofFinely divided, comminuted or powdered catalyst, preferably passing a200 to 300 mesh screen, is stored in a hopper l and drawn through line 8by a screw conveying means I0. Hydrogen or a gas rich in free hydrogenis supplied through line Il, passes through a heating means l2 andthence` flows through line i3 `into and through a blowing means I4. Hothydrogen is forced at high velocity through line I5 into which powderedcatalyst` is forced ,by screw conveying means I0 through line I6. meansvIll is one which can build up a pressureof 200 or more pounds persquareinch. A line' I6-a may be provided through which steam or inert gas Vmaybe injected into line IS to prevent leakage of hydrogen from line I5winto the screw Vconveying means.` The mixture of hydrogen and finelydivided catalyst is then introduced at high velocity into vthe top ofthe reaction chamber 4 `through a jet or nozzle which dischargesim-`mediately below the point at which the heated vapors are introduced. Thetwo streams impinge upon each other and a thorough and inti- Screwconveying gen is formed.

The. reaction products containing suspended catalyst are removed fromreaction chamber 4 through line |'l and pass thence into a cooling means|8 wherein the products are partially condensed. From cooling means i8the products pass through line I9 into a separating means 20 Awhereinthe liquid products containing the nely divided catalyst particles areseparated from the uncondensed products. f

The liquid products are removed from separating means 20 through line 2|and pass thence into line 23 and is introduced into a steaming chamber24 wherein the adsorbed oil and vapors are steamed out of it. Thethoroughly steamed and purged catalyst is then conveyed by a. meansdiagrammatically designated as line 25 into a regenerating means 26wherein the contaminants are removed from the catalyst by treatment withsteam or other inert gases containing controlled quantities of air oroxygen. The coke and tarry matter is thus removed by combustion, ca rebeing taken not to allow the combustion to proceed too rapidly.

From regenerating means 26 the regenerated catalyst passes through aconveying means denoted by line 21 into another steaming chamber 28wherein all oxygen and other gases are purged out of the catalyst bylmeans of steam or evacuation. The regenerated and purged catalyst isthen conveyed by means denoted by line 29 into the hopper I fromwhich itis again introduced into the reaction chamber in the manner previouslydescribed.

It will be understood that it may not be necessary to regenerate thecatalyst after each passage through the reaction chamber and in suchevent the catalyst may be returned directly to the hopper from thesteaming chamber 24. This may be done by means of valved line 30connecting line 25 with line 29.

Going back to the separating means 20 and the lterlng means 22, theuncondensed products are removed from separating means 20 through line3| and introduced into a fractionating means 32. Similarly, the ltratefrom ltering means 22 is removed through line 33 and preferably afterpassing through a heating means 34 passes through line 354intofractionating'means 32.

The heavier fractions boiling above the motor fuel range are removedfrom fractionating means 32 through line 36 and may be withdrawncomcarbons the gasesefroxn separating means 4| are passed through line43 into an absorbing means 44 wherein they are caused to ilow in countermate mixture of oil vapors, catalyst and hydrocurrent to an absorber oilsuch as a gas oil or heavy naphtha. The absorber oil absorbs most of thehydrocarbons except the methane. The fat absorber oil is removed throughline 45 and the unabsorbed gases consisting principally of hydrogen andmethane are removed through line 46 and may thence be returned to thesystem through'the blowing means I4 and line l5.

In the operation of the process the oil and hyl tween say -900 and 1000F. would be suitable.

The oil and hydrogen are introduced into the reaction chamber under apressure which may range from 100 to 1000 lbs/sq. inch, althoughmoderate pressures between 200 and 400 are preferable. A

The quantity of hydrogen used may vary between 1000 and 6000 cu. ft. perbarrelof oil, but quantities between 2000 and 3000 cu. ft. aresufiicient in most cases.

The ratio of catalyst to oil may Vary from about-3 parts by weight ofcatalyst to 1 part by weight of oil to as little as .05 part by weightof catalyst to 1 part of o'il. In most cases from .0S to 1.5 parts ofcatalyst to 1| part of oil will be suiiicient to give highlysatisfactory results.

The quantity of hydrogen necessary to suspend these quantities ofcatalyst will in general be far less than the quantity of hydrogen it isdesired to use in the process.

It is found that by carrying out the catalytic reaction in the presenceof hydrogen under these special conditions, the active life of thecatalyst is not only greatly lengthened, thus making the necessity forregeneration less frequent, but the yields and quality of the productobtained are markedly better than those of the product obtained whencarrying out the process in the absence of hydrogen and under lowerpressures. By

bustion. The quantity of oxygen in the regenery ating gases ispreferably relatively low at the -pletely from the process through line31 or may be returned to the process through line 38.

start of the regeneration cycle when combustion is rapid but may begradually increased as the coke is burned oil until near the end of thecycle the quantity of oxygen reaches a maximum. This is to avoidexcessive temperatures being developed. In general, it is best to keepthe maximum temperature during regeneration below about 1200 to 1300 F'.Higher temperatures are apt to impair the activity of the catalyst. The

regenerating gases may consist of nitrogen, flue gases, steam or otherinert gases and 4 to 10% oxygen, and are preferably heated to atemperature between 600 and 800 F. before being introduced into theregenerating means. Both before and after regeneration, the catalystshould be' thoroughly purged with steam or subjected to a vacuum lorboth.

The catalysts' used may be selected from a wide variety of materials.Natural clays or acid activated clays of the bentonitic' type aresuitable.

Synthetic clays such as activated alumina and silica either alone orimpregnated or mixed with- -other materials may be used. Alumina orsilica impregnated with solutions of salts of metals of group VI of theperiodic system such as molybdenum, tungsten and chromium, or aludividedcatalytic material suspension at high velocity into the reaction chamberat a point close to the point ofintroduction of the oil vapors, wherebya thorough mixture of oilvapors, hydrogen and nely divided catalyticmaterial is formed, removing the products of reaction from the reactionchamber, partiallycondensing the same, separating the finely dividedcatalytic mamina or silica mixed with oxides or suldes of these metalsare especially effective. It is found that sulfur or sulfur-containingcompounds help to maintain the activity ofthe catalysts. Hydrogensuliide, carbon disulfide, free sulfur or other sulfur supplyingsubstances may therefore be introduced into the reaction zone from timeto time or continuously in quantities suillcient for 'this purpose.

As indicated above, the catalytic process is operated under conditionssuch that there is substantially no net consumption of hydrogen.' lAs aresult, it will be seen that fresh hydrogen need only be introducedduring the early stages of the process because it may be continuouslyre- 4cycled in the manner described` by removing most of theuncondensable hydrocarbon gases.

' As the recycled gas becomes poorer in hydrogen,

either fresh hydrogen may be introduced or the pressure may be increasedto increasethe partial pressure of the hydrogen.

This type of operation is generally applicable to all types of catalyticprocesses for treating hydrocarbon oils. While it has been describedwith particular reference to catalytic cracking, it will be understoodthat slight variations in the temperatures and pressures and quantity ofhydrogen may be made to adapt it for other catalytic processes such ascatalytic reforming, catalytic dehydrogenatlon, catalytic gas reversionand the like.

Hydrocarbon oils from any source may be subjected to catalytic treatmentaccording to the present process, for example, virgin or cracked oilsderived from petroleum, oils derived from the destructive distillationor destructive hydrogenation of coals, tars, mineral oils, peats,lignites, shales, bitumens, or oils derived by synthetic processes suchas the Fisher Synthesis.A

This invention is not limited by any theories of vthe mechanism of thereactions, nor by any details which have `been given merely forpurterial from the liquid products, the reaction zone being maintainedunder a pressure between 200 and 400 lbs/sqyin., the quantity ofhydrogen present in the reaction zone beingbetween 2000 and 4000 cubicfeet per barrel of oil and the other conditions of operation beingadjusted vis-a-vis the pressure and quantity of hydrogen so that therewill be no net consumption of the hydrogen in the reaction.

3. An improved process for the catalytic treatment of hydrocarbon oilsat elevated tempera- .tures and in the presence of hydrogen underconditions such that there is no net consump tion of free hydrogen,which comprises Vaporizing the oil, introducing the oil vapors at highposes of illustration but is limited only in and' by the followingclaims in which it is intended to claim all novelty inherent in theinvention.

I claim: 4 1. In a catalytic process for treating hydrocarbon-oils invapor phase at elevated temperatures andl inthe presence of a ilnelydivided solid catalytic material, the improvements which comprisecarrying out the process in the presence of hydrogen under conditionssuch that there is no net consumption of free hydrogen, and introducingthe finely divided solid catalytic material velocity into a reactionchamber, separately heating a stream of hydrogen, introducing iinelydivided catalytic material into the vstream of heated hydrogen,introducing the stream of hydrogen containing suspended i'lnely dividedcatalytic material at high velocity into the reaction chamber at a pointclose to the point of introduction of the oil vapors, maintaining thereaction chamber under a pressure between 200 and 400 lbs/sq. in.,withdrawing the products of reaction, partially condensing the same,separating the 4finely divided catalytic material from the liquidproducts, separating the hydrogen and methane from the gaseous productsand returnf ing the iinely divided catalytic material in suspension inthe hydrogen and methane to the forming hydrocarbon oils to producehydrocarbons of high octane number suitable for motor fuel, whichcomprises Vaporizing the oil, separately heating a stream of hydrogen,introducing a iinely ldivided catalytic material into the stream ofhydrogen, introducing the vaporized suspended in the hydrogen into thereaction zone at a point close to the point of introduction oi the oilvapors to be treated, whereby a thorough mixture oi? oil vapors, finelydivided cata-` lytic material and hydrogen is formed.

2. Animproved process for catalytically treating hydrocarbon oilat'elevated temperatures which comprises vaporizing the oil, introducingthe oil vapors at high velocity into a reaction chamber, separatelyheating a stream of hydrogen, introducing nely divided catalyticmaterial into the stream of heated hydrogen, introducing the stream ofhydrogen containing finely oil and hydrogen containing finely dividedcata-- lytic material in suspension at high velocity into the reactionchamber at closely spaced points' whereby a thorough mixture of oilvapor, hydrogen and iinely divided catalytic material is formed,maintaining the reaction chamber at a temperature between 900 and 1000"F., under a pressure between 200 and 400 pounds per square inch in thepresence of quantities of hydrogen regulated between 2000 and 4000 cubicfeet per barrel of oil and adjusting the other conditions of operationvis-a-vis the temperature, pressure and quantity of'hydrogen so thatthere will be no net consumption of free hydrogen in the reaction,withdrawing the 'products of reaction, partially condensing the same,nltering the finely divided catalytic material from the liquid cproducts, removing the contaminating material deposited on the finelydivided catalyst by combustion, recovering the free hydrogen from the 7.Process according to claim 6 in which the catalytic material is a nelydivided adsorptve clay passing a 300 mesh screen. 8. Process accordingto claim 6 in which the catalytic material is finely divided aluminacarrying a compound of a metal of the Sixth Group of the PeriodicSystem.

ROBERT P. RUSSELL.

